PD Dr. Hans-Gregor Hübl

Courses and Dates

Offered Bachelor’s or Master’s Theses Topics

Controlling magnon transport in antiferromagnetic insulators

In antiferromagnetic insulators, we obtain two magnon modes with opposite spin chirality due to the two opposing magnetic sublattices. In this way, magnon transport in antiferromagnetic insulators can be considered as the magnonic equivalent of spin transport via electrons. The aim of this thesis is to obtain a better understanding of the magnon transport in antiferromagnetic insulators and investigate external control parameters that allow a manipulation of the spin information transport in the antiferromagnetic insulator. Moreover, these experiments allow to extract important transport properties like for example the magnon spin life-time. We are looking for resourceful master student heavily interested in these magnon transport experiments. In order to answer questions regarding magnon transport in magnetic insulators, your thesis will contain aspects of the fabrication of nano-scale devices using electron beam lithography as well as ultra-sensitive low-noise electronic measurements in a cryogenic environment.

suitable as

• Master’s Thesis Condensed Matter Physics

Supervisor: Rudolf Gross

Superconducting devices based on superconductor/ferromagnet heterostructures

The combination of ferromagnetic and superconducting materials leads to intriguing proximity effects at the interface of the two materials. The goal of this thesis is to investigate the spin transport of superconductor/ferromagnet interfaces and model the obtained results in the framework of proximity effects. To this end, we will fabricate superconducting devices based on superconductor/ferromagent heterostructures with a special focus on controlling magnetization dynamics via superconducting charge currents. This requires investigations at low temperatures around the critical temperature of the superconductor in large magnetic fields. In addition microwave magnetic fields will be employed to drive magnetization dynamics in the ferromagnet and excitations in the superconductor. We are looking for a talented master student to investigate spin transport in superconductor/ferromagnet heterostructures. You will fabricate superconductor/ferromagnet heterostructures using our new UHV sputtering system. As a next step, you will structure these blanket films with optical and electron beam lithography into superconducting devices. Finally, you will characterize your fabricated samples at low temperatures utilizing superconducting magnet cryostats. Here, high frequency spin dynamics as well magnetotransport studies are the focus of your thesis.

suitable as

• Master’s Thesis Condensed Matter Physics

Supervisor: Rudolf Gross